Optimal Design of a Permanent Magnet Synchronous Motor Using the Cultural Algorithm

In this paper, a permanent magnet synchronous motor (PMSM) structure is optimized by a single-objective optimization method known as the cultural algorithm (CA). The torque capability of the PMSM is high due to the presence of the permanent magnets (PMs) in its structure. However, in critical applications with limited space (especially with volume limitation), the torque density is a more prominent function than the torque. For this reason, in the optimization problem presented in this paper, the torque density is the objective function. Therefore, this study aims to maximize the torque capability at a specified space besides maintaining the torque ripple under a specified value (as a constraint). To this, the structural parameters of the machine are optimized by the CA. An additional decision variable is also considered, and an important effect is concluded from that. The mathematical basics of the CA, operators, and other settings of the algorithm are also introduced. The results of the optimization process would be presented and compared with the initial machine design. These results demonstrate that the CA increases the torque density of the machine and keeps the torque ripple under the specified value. After the optimization results and comparisons, the electromagnetic performance of the motor is presented.